1. Field of the Invention
The present invention relates to a digital TV and more particularly to a digital TV equipped with a general-purpose CPU and a signal processing method therein.
2. Description of the Related Art
As the convergence trend of digital consumer electronic appliances has been accelerated, a digital TV with which digital broadcasting can be watched has begun to process applications, such as games and Internet browsers, in order to provide a variety of services to users in addition to reception of broadcasting. Accordingly, the digital TV now requires a high-end CPU capable of processing more data. Since the capability of an ARM or MIPS CPU that is a conventional embedded CPU is not enough to be used in a digital TV requiring a CPU with a 500 MHz or higher speed, a digital TV employing an x86 processor that is a general-purpose CPU instead of the conventional CPUs has been introduced.
FIG. 1 illustrates a structure of an ordinary x86 system.
As illustrated in FIG. 1, an x86 system can be split into two parts centering around a north bridge and a south bridge, respectively. The north bridge connects a CPU, a memory, and a PCI bus, and provides a high data rate. The south bridge manages relatively slow data lines connecting peripheral devices, such as a hard disc data line, a USB bus, and an ISA bus, and can be connected to the CPU through the north bridge.
When this system is applied to a digital TV, digital broadcast data received in an MPEG transport stream form is decoded by an MPEG decoder and the decoded broadcast signal is transmitted to a graphic processor through a PCI bus. Meanwhile, graphics related to an application, such as a web browser, is generated by the x86 CPU and transmitted to a video processor. The video processor synthesizes and processes the graphics and outputs the result to a display apparatus.
FIG. 2 illustrates a booting process in a conventional digital TV in which an x86 is mounted. Since an x86 system has a general-purpose architecture unlike an embedded system, if the power is turned on, the CPU, the system memory and peripheral device do not immediately communicate with each other and operate, and a series of booting operations are required. This booting process includes turning on the power supply, executing a BIOS program, loading an operating system, and loading device drivers. Only after this booting process is completed, elements of the system operate such that a user can watch digital broadcast and application graphics, such as a web browser. Since it usually takes 8-20 seconds to perform this booting process, the user has to wait until the booting process is completed after turning on the digital TV.